Desmos provides a free, beautiful online graphing calculator. I collaborated with the Desmos team (designers & engineers) to design elements of the user experience & interface design. I also participated in the creation of the free iPad app, which you can download for free here. I helped work on the inital stages of the Android app as well (not pictured). To try out the desktop version of the calculator which you see below, click here.
In addition to the desktop calculator, I helped work on top secret projects :)